Saturn

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What a sight this is in the telescope! In many ways there is nothing to rival the real time appearance of this planet, as it seems to hang in space like a luminous flying saucer (Figure 6.9). It responds very favorably to CCD video imaging, but you will probably find that soon you want to try to capture the additional subtleties that you see in the eyepiece. By comparison to video, drawing it is another matter entirely, as Saturn is amongst the greatest challenges to our drawing skills that we are likely to face. Additionally, satisfactory blank disks of Saturn are extremely hard to produce, the greatest difficulty being the ever-changing tilt and aspect of the rings. The Crepe Ring and its shadows on the disk only compound this further. You might use a current video image, blanked out and enlarged to appropriate size as a template. I have found a satisfactory solution has been to draw the planet and rings freehand, with accurate proportions being established at the outset. This can easily be accomplished by

Figure 6.8. Jupiter 2001: 6 January 2001, 6-1 1:30 pm, 229x (blue filter)/343x (no filter), seeing scale II.

Figure 6.9. Video image of Saturn, November 2001. The rings are almost fully open, with shaded zones on the rings. Note the prominent belt and two others, the dark polar region, the absorption zone made by the Crepe Ring, and almost perfect alignment of the planet relative to the Sun and Earth, since there is only a slight wedge of shadow from the disk on the rings themselves.

marking on the paper small dots at the outermost and innermost places (check these dimensions from any photograph or video image), and then outline the body and rings of the planet itself to correspond to the planet's appearance at the time. Since I don't draw Saturn more than once or twice a year (for obvious reasons to anyone who tries it), I can afford to let each drawing be more time-intensive than would normally be the case with other subjects.

Instead of an entirely black background extending to the corners of the page, I use a black pencil on white paper to suggest black space around the planet. This consists of dark shading outlining the planet and rings, continuing outwards but gradually reducing its intensity until it blends into the white of the paper. It is also drawn with linear motions parallel to the plane of the planet, for a clearer effect that does not compete with the orientation of the rings. Having done this, capturing the coloring and relative brightness of the rings should not pose too much of a problem, and the disk itself should be a "breeze" after the challenges of Jupiter.

The sheer beauty of this planet is mesmerizing, in ways only live viewing can provide. The overall color is something of a deep yellow-gold, and even small telescopes will put on a worthy show. The variations of hues on Saturn are less obvious than on Jupiter, and the changes from month to month are far slower, and may not be detectable for much longer periods. The number of cloud belts visible also will be fewer than on Jupiter, and the contrast between belts and zones more subtle. These cloud belts do not normally exhibit such turbulent variations and detail as do Jupiter's, but you should be able to detect a typical equatorial belt redness versus distinct grays of the polar regions, and sometimes entire regions may be lighter than the surrounding area. Spots are more unusual, and certainly harder to see, although there have been some notable sightings over the years. Perhaps the most famous of these was the Great White Spot discovered by British comedian Will Hayes in the 1930s, and long since faded into history.

Look for variations in the entire ring system itself; you will see areas of light and shade. The Cassini Division is an easy mark; not so the infamous Encke Division, which is often confused with a dark zone within the outer A-ring, closer to the planet than the Encke feature. It took spacecraft to confirm its existence undeniably since it was too fine to show itself on photographs before the time of space exploration. As far back as the nineteenth century, certain noted observers also reported seeing structures on the rings themselves, which seems to suggest that they did in fact see traces of the famous "spokes" shown in views obtained by much more recent spacecraft. At the time these could not be confirmed by other astronomers, but now it would appear there was something to these old observations. Today, with firm confirmation of their existence, some amateur observers also have claimed to have discerned suggestions of the "spokes", eye preparation again revealing things previously unseen and unknown. As of yet, I cannot join their ranks, but maybe you will. With little more than small apertures the Crepe Ring becomes possible to see; its transparency and bluish-gray color become more apparent with increasing aperture (probably anything 8 inches or more) and darker immediate surroundings. Be sure to baffle your backyard suburban sight against light intrusions. Most good telescopes above 6 inches will reveal the Crepe Ring, though in larger apertures it is very striking, its subtle coloration and appearance likely to require these larger instruments.

Unless the seeing is at its best, any fine details on Saturn are notoriously difficult to detect, although the total image of Saturn, including its rings, appears quite sizeable and about the equal of Jupiter. The actual disk is very much smaller, approximately a third of the whole. You will find, however, that this planet is quite capable of withstanding some very high magnifications on good nights, far higher than with most other objects. On one notable evening many years ago with my old 12--inch reflector I was able to use the astounding magnification of 720x, with the greatest clarity and ease!

The main drawing in Figure 6.10 was made on a particularly good night when the air was almost still; the planet was placed at one of its most beautiful positions relative to us, with an almost fully open ring system for us to see. It is a good example of an entirely freehand drawing, made according to the guidelines previously discussed. The complexities also explain why I don't draw Saturn too often! Don't be misled by my drawing; although it is a very close representation of the visual appearance of Saturn that night, the so-called Encke's Division near the outer edge of the ring system, at 0.1 minute of arc, is actually beyond the diffraction limit of even an 18-inch telescope such as mine. However, I do believe on the night that I drew the planet, I did indeed glimpse something of it, as has been the case with other observers viewing similar high contrast planetary features. I don't believe I mistook it for the dark feature within the A-Ring. Encke's Division is so routinely and glibly described by so many of today's amateurs that you will begin to think that you or your telescope

Figure 6.10.

Drawing of Saturn: 28 November 1999, 10:45 pm, 343x, seeing scale II.

Figure 6.10.

Drawing of Saturn: 28 November 1999, 10:45 pm, 343x, seeing scale II.

are at fault if you have failed to see it. It is not likely that most of these claims can be substantiated, as very few amateurs possess instruments of sufficient aperture to reveal such a fine feature. It is difficult even with 40 inches, and certainly requires excellent seeing. Here again we can see how the eye has a better chance of seeing something, once it knows how it should appear. But remember, there is a fine line between seeing and convincing ourselves we see something which we can't. As always, be vigilant for the truth.

The aspect of the rings relative to us is affected in exactly the same way as are the variations in Mars' appearance from year to year. The changes we perceive are affected by the axial tilt of the planet relative to us. It has nothing to do with the rings themselves "opening and closing"! This remarkable phenomenon of our relative planetary positions occurs over approximately a 15 year cycle, and produces incredible variations in the appearance of the planet, not only in the angle that the rings present themselves, but also in shadows projected on them by the planet itself.

In order to show the appearance of the rings in a largely edge-on position relative to our line of sight, it was necessary to utilize a drawing made long ago with my old 8--inch reflector (Figure 6.11). I simply have not had the 18-inch enough years to provide the range that the rings show us. However, accessing drawings made long ago only illustrates one of the great pleasures to be enjoyed by having a collection of images made over many years. (This old drawing, from 1967 does not, of course, exhibit the resolution that I enjoy these days, and was also made in black-and-white.)

Figure 6.11.

Drawing of Saturn: 22 October 1967, 10:15 pm GMT; 200x 8 j-inch reflector, seeing scale II. The rings are almost edge-on, the Crepe Ring is just detectable, and the planet has a bright equatorial zone.

Figure 6.12.

Drawing of Saturn: 16 April 1974, 9:10 pm Eastern Time; 167x 3-inch refractor, seeing scale I. The rings are fully open, and there is a shadow on the preceding side; compare with Figure 6.9.

Figure 6.12.

Drawing of Saturn: 16 April 1974, 9:10 pm Eastern Time; 167x 3-inch refractor, seeing scale I. The rings are fully open, and there is a shadow on the preceding side; compare with Figure 6.9.

Also possibly of interest to you is another drawing (Figure 6.12) made through a smaller telescope yet (a 3-inch refractor I had for some years). Both it and the drawing above show just how well these smaller apertures can perform on planetary subjects. Although detail is noticeably less with both of these drawings than through the large scopes available to amateurs these days, the breathtaking nature of this almost surreal subject still shows superbly. It will indicate just how successful you will be with practically any aperture you might turn on it.

A comment on viewing the satellites: unlike those of Jupiter, which, with large enough apertures occasionally provide us opportunities to glimpse surface detail, those of Saturn will not grant any such favors to us. The majority are simply too far away and small to see as scarcely more than star-like points. Many observers nevertheless enjoy witnessing the interplay between the visible satellites themselves, the planet and its rings.

Saturn is probably the crowning glory of our short tour around the best of the Solar System, but it is now time to move on to the great expanse beyond. This, of course, is the realm so often written off for suburbanites as being hopelessly ruined by our cities. While I aim to show how we may access some of that lost realm and what part of it is available to us, we should always take advantage of the Moon and planets whenever they are observable in the sky. All we need is steady air, a clear enough horizon, and the curiosity to explore.

Chapter 7

Deep Space -Visual Impressions and Expectations: The Primary Catalog

The listing of deep space objects featured and described later in this chapter represents, in my view, the finest sights available to the Northern Hemisphere suburban dweller. Many are visible from the Southern Hemisphere as well. Almost without exception, few of these sights will be in the realm of the spectacular in the absence of any image enhancing equipment as described earlier. Because of the nature of them, we will do best on nights of best transparency, just as we would at a dark sky site. I have included real time illustrations of all of the objects themselves individually, as well as some comments on observing them. Generally, I leave detailed scientific and historical background about these marvelous sights to the many excellent reference sources that already exist; it has never been my intention to repeat material so readily available. I think it is also important to point out that from the suburbs it is usually not realistic to expect to see the kinds of extensive subtle detail one would observe from prime dark sky sites, so painstakingly described in many other volumes on the deep sky. This is not to say that the objects will not appear stunning or detailed; but in all fairness to you and your expectations, I will not pretend to see in them more than I have been able to. It is instead my hope that I can provide you with a realistic expectation of what you may be able to see from your city-bound backyard, and how these objects might appear to you.

Next to each listing, I have included some relevant information, depending on the type of object. These statistics (with the exception of the coordinates, updated to present values) are according to Burnham's Celestial Handbook. This source seems to me to be the most reliable source in its assessments. Others often seem overly optimistic regarding estimated visual magnitudes. Anticipating unrealistic object magnitudes may be quite disappointing for observations based on such estimates; Burnham seems much closer to the mark. However, just what you will see depends on a number of factors: your telescope's aperture, magnification used, clarity of sky, whether an image intensifier or light filter is employed, etc., the quality of all those things - plus, of course, your location. In considering these various factors, and the differences with your actual observations of the objects listed below, the answer is not as obvious at first as it may seem. The lowest magnification of a larger aperture will be much greater than that of a lesser aperture, but in illumination of the field, at any rate, the advantages of the larger size will be somewhat negated by the light diminution of its higher minimum power. So although the resolution and image size will not be of the same order with a smaller aperture, the results with most of the objects in this chapter should be pleasing with moderate-to-large telescopes in less than favorable conditions. Your visual expectations should not be too far out of line with what is shown in the illustrations, and they should serve as a reasonable guide.

All video images in this chapter were taken with the set-up described in Chapters 2 and 4, with my 18-inch reflector. Similarly, the drawings were made directly from observations (either with intensification, a light filter, or no added means at all), as outlined in the main listing. Be sure to experiment with everything available to you and not just according to my recommendations, since these reflect my own circumstances and preferences only. However, these recommendations will at the very least serve as a reliable basis for your own viewing methods. The deep space illustrations are also of several types: direct real time images from the image intensifier via a CCD video camera, drawings from observations with the image intensifier, drawings as observed through a narrowband light filter (and occasionally without), and a few others representing the combined separate views through filter and then intensifier. I do not specify the power used, but usually the image scale approximates the effect of what I experienced at the time using low-to-moderate powers. In my own case, this usually corresponds to around 80x or 160x. High power was rarely more than 240x for deep space subjects. (Occasionally, when a higher power was used, it is noted as such.)

The reality of "seeing" is seldom as obvious as you might anticipate. The images, particularly with some galaxies, will sometimes not be as bright as you might expect. In time, this ceases to be a factor, as your mind and eye will make their own relative adjustments. On the whole, you will notice a large gap between their grand observatory portraits and what is presented in the real time views; conversely, you may also be surprised when the reality comes close to the best photographs. When what you are seeing seems less obvious, don't be led astray. With perseverance, knowledge of what is really there, as well as what to expect, you will marvel at being able to discern so much, including so many subtle traces of all you know to be present. These subtleties will look just as good to you as if you saw their fully resolved being. You will share in the same wonder of real time viewing that has inspired me all these years; it is as if you have some direct contact with other places across the vast distances of space. Amazingly, some of this even holds true when viewing live on the TV monitor, which should be good news for those using Astrovid's StellaCam EX or SBIG's STV. And to think we are experiencing all of this in surroundings that have been deemed unfit for such observations by most serious observers!

There really is no shortage of grand deep space sights for us to enjoy from the city. In the individual descriptions that follow, I have included some visual information to guide you in this "most successful sights" primary list. The real time deep space images are presented without making them appear superior to the way they appeared to me at the time, as viewed directly through the eyepiece, intensified or otherwise. Most were made (drawings included) in the typical, mediocre suburban sky conditions that I experience the majority of the time from my location, and with which this writing is primarily concerned. Any adjustments to the video images were made only when it was necessary to make the contrast closer to that of the view through the eyepiece. Aside from this, the only allowance you might grant is in the slightly "digital" and less than perfectly defined appearance of some of these images (particularly in the enlarged examples). One has to remember that they are simple video images after all, basically unprocessed, and remarkable for having been captured in real time. In a straight comparison, image to image, obviously they will not usually compare with time exposure photography or CCD imaging. The crispness, brilliance, and detail of the live view, either direct through the image intensifier or to some degree on the video monitor, is also impossible to transfer to the page; the printing process reduces this further. However, these video snapshots, in conjunction with drawings provided wherever possible, will provide you with a remarkable degree of preparation for your own real time viewing.

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